[Cmake] Need something sticky

[John Biddiscombe]

vtk cmakelists files follow the general trend of

define sources
#include localuseroptions
wrap tcl

unfortunately, I need to add some special compiler flags to the tcl sources, but I can't do this in localuseroptions because they don't yet exist.

One solution is to 

define sources
#include localuseroptions
wrap tcl
#include localuseroptions2

but this seems a bit rubbish and I don't like seeing all my files modified under cvs and would would like to keep my copy clean if possible.

another solution is to move the localuseroptions
define sources
wrap tcl
#include localuseroptions

but I had that request turned down previously.

And another solution might be to allow me to put
  SET_SOURCE_FILES_PROPERTIES(${CommonTCL_SRCS} COMPILE_FLAGS -H="$ENV{TEMP}/vtk/vtk.csm")
in localuseroptions but make it sticky in some way. Then later when 
  VTK_WRAP_TCL(vtkCommonTCL CommonTCL_SRCS ${Common_SRCS})
is called, any files added will pick up the flags

good? yes? no?

JB